1. Field of the Invention
The present invention relates to a monitor calibration method, monitor calibration equipment, and a storage medium storing a program for executing the monitor calibration method, all of which aid the viewer in detecting the black point of a monitor display.
2. Description of the Related Art
Generally, monitors such as CRT display-type monitors have a nonlinear display relationship between the RGB input value and the brightness, as shown in FIG. 1. Any input value below a certain input value BP has a brightness of zero and is therefore not visible to humans. This input value BP is referred to as the black point.
The black point can be changed by adjusting functions such as brightness on the monitor itself. The black point also fluctuates due to deterioration of the monitor caused by aging and to slight differences in human vision. By finding the black point in order to learn the relationship between the input values and the images displayed on the monitor, the same color tones as those displayed on the monitor can be reproduced by a color printer or other device based on the discovered relationship.
A black point detection method has been proposed in the art, wherein, as shown in FIG. 2, the solid black display area Bk with an RGB value of 0 and a gray display are Gy with a variable RGB input value greater than 0 are displayed side by side on a monitor. A maximum RGB input value at which the display areas Bk and the disply area Gy cannot be distinguished is searched for by increasing and decreasing the RGB input value for the gray display are Gy. The black point is set to this maximum RGB value.
However, determining the black point according to the method described above results in a wide range of measurements, indicating that the method is insufficiently precise.
In view of the foregoing, it is an object of the present invention to provide a monitor calibration method, monitor calibration equipment, and a storage medium storing a program for executing the monitor calibration method, all of which can aid the viewer in measuring the black point of a monitor display with great precision. The following is a description of the features and benefits of the present invention.
The monitor calibration method of the present invention aids a viewer in detecting the black point of a monitor by displaying a solid black display area and a gray display area adjacent to one another and gradually changing the brightness of the gray display area from light to dark or from dark to light, wherein at least one portion of the solid black display area is interposed in the gray display area and at least one portion of the gray display area is interposed in the solid black display area. Here the solid black display area is an area in which the pixels are displayed in solid black, that is, with an input value of 0. The gray display area is an area in which the pixels are displayed with an input value greater than or equal to 0. However, it is not necessary to include 0 in the possible range of input values for the gray display area.
In a monitor calibration method of the prior art, shown in FIG. 2, the gray display area Gy is sandwiched by the solid black display area Bk. However, the solid black display area Bk is not sandwiched by the gray display area Gy.
In the present invention, at least one portion of the solid black display area is interposed in the gray display area and at least one portion of the gray display area is interposed in the solid black display area. In other words, at least a portion of each area is sandwiched by the other area. The difference in brightness seen in the gray display area sandwiched by the solid black display area appears differently from the difference in brightness seen in the solid black display area sandwiched by the gray display area. By looking at both appearances simultaneously, even a subtle difference in brightness between the two display areas is visually striking. Hence, a very accurate black point can be determined.
One example for sandwiching at least one portion of each area by the other area is for the solid black display area and the gray display area to be stripe-shaped and arranged alternately. Further, if the alternately arranged stripes of the solid black display area and the gray display area have a width of between {fraction (1/72)} and xc2xc inch, and in particular a width of between {fraction (1/36)} and xe2x85x9 inch, a very accurate black point can be determined.
The monitor calibration method of the present invention aids a viewer in detecting the black point of a monitor by displaying a solid black display area and a gray display area adjacent to one another and gradually changing the brightness of the gray display area from light to dark or from dark to light, wherein one portion of either the solid black display area or the gray display area is surrounded by the other display area.
In the prior art shown in FIG. 2, neither the gray display area Gy nor the solid black display area Bk is surrounded by the other display area. In the present invention, however, one portion of either the solid black display area or the gray display area is surrounded by the other display area. For this reason, a display area abuts another display area not only on the left and right (nor only up and down), but left and right, up and down, and diagonally. Hence, even a subtle difference between the two display areas is visually striking, and a very accurate black point can be determined.
Further, the display area that is surrounded by the other display area can be formed in a specific shape, such as the shape of a star, alphanumeric characters, or the like. It is desirable if the shape formed by this display area contains portions having a width of between {fraction (1/72)} and xc2xc inch, and particularly contains portions having a width of between {fraction (1/36)} and xe2x85x9 inch. Accordingly, a very accurate black point can be determined. The more portions of the display area that have this size of width, the more accurate the black point determination will be.
In addition to the above-described monitor calibration method, it is possible to include a process in which the brightness of the solid black display area and the gray display area are periodically exchanged, while the brightness of the gray display area is gradually changed from light to dark or from dark to light.
Through this process, the borders between the solid black display area and the gray display area will always be emphasized so that even a subtle difference in brightness between the two display areas is visually striking. Hence, a very accurate black point can be determined.
Alternatively, it is possible to perform a process in which the gray display area is periodically displayed in solid black, while the brightness of the gray display area is gradually changed from light to dark or from dark to light. Hence, because the gray display area is switched back and forth between displaying solid black and displaying gray, while the brightness of the gray is gradually changing, the borders between the solid black display area and the gray display area will always be emphasized so that even a subtle difference in brightness between the two display areas is visually striking. Hence, a very accurate black point can be determined.
The monitor calibration method of the present invention aids a viewer in detecting the black point of a monitor by displaying a first gray display area and a second gray display area adjacent to one another and changing the brightnesses of the two display areas from light to dark while either maintaining the difference in the two brightnesses or decreasing the difference between the two brightnesses, or changing the brightnesses of the two display areas from dark to light while either maintaining the difference in the two brightnesses or increasing the difference between the two brightnesses.
Therefore, instead of a solid black display area, two gray display areas with different brightnesses are used, and a very accurate black point can be determined by changing the brightnesses of the two display areas from light to dark while either maintaining or decreasing the difference in the two brightnesses, or by changing the brightnesses of the two display areas from dark to light while either maintaining or increasing the difference in the two brightnesses.
Since the brightnesses for both a first gray display area and a second gray display area are changed in order to determine the black point, it is possible to acquire an appropriate and more precise black point input value for use in actual image displays by the dynamically changing brightness of the entire display.
In this case as well, it is desirable for at least one portion of the first gray display area to be interposed in the second gray display area and at least one portion of the second gray display area to be interposed in the first gray display area in order to determine a more accurate black point. Further, it is desirable for the first gray display area and the second gray display area to be stripe-shaped and arranged alternately. The alternately arranged stripes of the first gray display area and the second gray display area should have a width of between {fraction (1/72)} and xc2xc inch, and particularly a width of between {fraction (1/36)} and xe2x85x9 inch in order to determine a more accurate black point.
Further, as described above, either the first gray display area or the second gray display area can be surrounded by the other display area, and the display area surrounded by the other display area can be formed in a specific shape.
As described above, the brightness of the first gray display area and the second gray display area can be periodically exchanged, while changing the brightness of the first and second gray display areas from light to dark and either maintaining or decreasing the difference between the two brightnesses, or while changing the brightnesses of the two display areas from dark to light and either maintaining or increasing the difference between the two brightnesses.
The brightness of the second gray display area can be periodically displayed with the same brightness as the first gray display area, similar to the method described above of periodically displaying solid black in the gray display area.
When applying the invention described above to the monitor of a computer system, a storage medium can be used for storing these monitor calibration methods in the form of an application program capable of being executed on a computer system.
Next, monitor calibration equipment necessary to achieve the monitor calibration methods described above will be described. Monitor calibration equipment of the present invention displays a solid black display area and a gray display area adjacently on a monitor display and aids the viewer in detecting the black point of the monitor display by gradually changing the brightness of the gray display area from dark to light or from light to dark. This monitor calibration equipment includes display area setting means for setting at least one portion of both the solid black display area and the gray display area so as to be interposed in the other display area on the monitor display; solid black display area control means for outputting display output of the minimum brightness to be displayed in the solid black display area set by the display area setting means; and gray display area control means for outputting display output which brightness is gradually varied from light to dark or from dark to light to be displayed in the gray display area set by the display area setting means.
The solid black display area and the gray display area set according to the display area setting means are stripe-shaped and arranged alternately. The alternately arranged stripes of the solid black display area and the gray display area have a width of between {fraction (1/72)} and xc2xc inch, and particularly of between {fraction (1/36)} and xe2x85x9 inch.
The monitor calibration equipment of the present invention displays a solid black display area and a gray display area adjacently on a monitor display and aids the viewer in detecting the black point of the monitor display. by gradually changing the brightness of the gray display area from dark to light or from light to dark. This monitor calibration equipment includes a display area setting means for setting one of either the solid black display area or the gray display area so as to be surrounded by the other display area on the monitor display; solid black display area control means for outputting display output of the minimum brightness to be displayed in the solid black display area set by the display area setting means; and gray display area control means for outputting display output which brightness is varied from light to dark or from dark to light to be displayed in the gray display area set by the display area setting means.
One of either the solid black display area or the gray display area can be formed in a specific shape. In order to find a more precise black point, it is desirable for the specific shape to contain portions having a width of between {fraction (1/72)} and xc2xc inch, and particularly of between {fraction (1/36)} and xe2x85x9 inch. Further, it is desirable to have many portions with the widths given above in order to find a more precise black point.
The monitor calibration equipment described above periodically exchanges the brightness of the solid black display area and of the gray display area, while changing the brightness of the gray display area from light to dark or from dark to light according to the solid black display area control means, which periodically displays in the solid black display area display output equivalent to the display output for the gray display area control means while at the same time the gray display area control means displays in the gray display area display output having the minimum brightness.
The gray display area control means can periodically output display output of the minimum brightness to the gray display area in order to periodically switch the gray display area to solid black.
The monitor calibration equipment aids the viewer in determining the black point of a monitor display. This monitor calibration equipment includes a display area setting means for adjacently setting a first gray display area and a second gray display area on the monitor display; first gray display area control means for outputting display output to the first gray display area set by the display area setting means; second gray display area control means for outputting display output to the second gray display area set by the display area setting means which output is different from the display output of the first gray display area control means; and display output control means for controlling display output of the first gray display area control means and display output of the second gray display area control means so that the display output for both is changed from light to dark while the difference in the display outputs is maintained or gradually decreased, or so that the display output for both is changed from dark to light while the difference in the display outputs is maintained or gradually increased.
The display area setting means can interpose at least one portion of the first gray display area and at least one portion of the second gray display area in the other display area on the monitor display, and can set the first gray display area and the second gray display area in alternately arranged stripe shapes. It is desirable if the alternately arranged stripes of the first gray display area and the second gray display area have a width of between {fraction (1/72)} and xc2xc inch, and particularly of between {fraction (1/36)} and xe2x85x9 inch.
The display area setting means can set either the first gray display area or the second gray display area so as to be surrounded by the other display area on the monitor display. In this case, one display area can be formed in a specific shape.
The display output control means can be configured to periodically exchange display output of the first gray display area control means and display output of the second gray display area control means, while changing the display outputs from light to dark and either maintaining or decreasing the difference between the two display outputs, or while changing the display outputs from dark to light and either maintaining or increasing the difference between the two display outputs.
The second gray display area control means can be configured to periodically display in the second gray display area a display having the same brightness as the first gray display area.
In the present invention, the viewer of the monitor can also be an instrument used for measuring brightness and is not limited to a human viewer.
In the first embodiment of the present invention to be described later on, S100 is equivalent to the process of the display area setting means; S110 and S120 are equivalent to the process of the solid black display area control means; and S110 and S130 are equivalent to the process of the gray display area control means.
In the second embodiment, S100 is equivalent to the process of the display area setting means; S110 and S120 are equivalent to the process of the solid black display area control means; and S110, S130, S152, S154, S156, S170, S192, and S194 are equivalent to the process of the gray display area control means.
In the third embodiment, S100 is equivalent to the process of the display area setting means; S110, S120, and S196 are equivalent to the process of the solid black display area control means; and S110, S130, S170, and S196 are equivalent to the process of the gray display area control means.
In the fourth embodiment, S100 is equivalent to the process of the display area setting means; S120 is equivalent to the process of the first gray display area control means; S130 is equivalent to the process of the second gray display area control means; and S112 and S170 are equivalent to the process of the display output control means.